In the chemical process industry, there often is used a type of equipment in which particulate materials may be dumped for further handling, commonly referred to as a bag dump station. Such stations generally consist of a hopper having an inlet opening through which bags of particulate material may be dumped manually, and an outlet opening typically communicating with a pneumatic conveying line, and a filter unit disposed within the housing of the station and in communication with the interior of the hopper which operates to draw airborne particles in the vicinity of the hopper into the interior of the hopper.
In the use of such dump stations, it has been found that spillage of particulate material often occurs or that the particular material to be dumped is contained in large drums which often are too heavy to be manually lifted and dumped as with smaller bag material. In an effort to recover such spilled material and also to accommodate the handling of drums too heavy to be lifted and dumped, a vacuum system has been developed utilizing an ejector for vacuuming spilled material and material contained in heavy containers. An example of such a vacuum system and ejector is illustrated and described in U.S. Pat. No. 5,769,572.
Although the type of vacuum system and ejector disclosed in the aforementioned patent have been found to be highly effective in handling particulate material which has been spilled or contained in a heavy drum, the ejector therefor has been found to be comparatively costly to fabricate and mount on the hopper of such dump stations. Furthermore, because of the tubular construction of such ejectors, it has not been possible to utilize abrasive-resistant materials in fabricating such ejectors, which are advantageous and preferable to use because of the abrasive properties of many particulate materials with which such ejectors have been used.